摘要
【目的】研究宰前热应激对肉鸡胸肉pH、脂肪氧化和蛋白质氧化的影响,探讨热应激影响宰后肌肉蛋白质功能特性的机制。【方法】将30日龄AA肉鸡由(25±1)℃突然暴露在(40±1)℃高温中,并分别持续0、1、2、3和5h后,各处理组中随机抽取10只,宰杀后剥取的胸肌在4℃条件下成熟24h,测定鸡胸肉的pH、脂肪氧化产物MDA、蛋白羰基值和蛋白质功能特性的变化。【结果】与对照组相比,热应激处理组的鸡胸肉pH30min、pH24h呈现下降趋势(P<0.05),3h和5h处理组提高了胸肉脂肪氧化程度(P<0.01),2、3和5h处理组胸肉肌浆蛋白和肌原纤维蛋白氧化程度高于对照组(P<0.01),热应激时间由1h到5h,胸肉蛋白质溶解度呈下降趋势,肉汁损失、压榨损失和煮制损失呈增加趋势,热应激处理组胸肉肌原纤维蛋白凝胶具有较低的硬度和弹性(P<0.01),热应激2、3和5h处理组胸肉肌原纤维蛋白凝胶保水性较对照组差(P<0.01)。【结论】宰前热应激引起宰后肉鸡胸肉的pH下降,促使肌肉脂肪和蛋白质氧化程度加剧,导致胸肉蛋白质溶解度和持水能力降低,对肌原纤维蛋白凝胶特性造成不利影响。
【Objective】This study was conducted to determine the effects of heat stress on pH,lipid peroxidation,protein oxidation and protein functionality in broiler breast meat. 【Method】Two hundred AA broilers were randomly divided into 5 groups,40 broilers for each group. After 30 days adaptive feeding under the normal temperature,broilers were suddenly stressed for 0,1,2,3 and 5 h by increasing environmental temperature from （25±1）℃ to （40±1）℃. The pH,lipid or protein oxidative status and protein functionality of 10 broiler breast muscles in every group were investigated. 【Result】As compared with the control group,the pH30min and pH24h of muscle decreased significantly （P〈0.05）,oxidative extent of intramuscular fat increased significantly at 3 h and 5 h （P 〈0.01）,oxidative extent of sarcoplasmic and myofibrillar protein also increased significantly at 2,3 and 5 h （P〈0.01）. A decreasing tendency was found in muscle protein solubility and water holding capacity from 1 h to 5 h. Lower hardness and springness was observed in myofibrillar protein gels of breast muscles in heat stress groups （P〈0.01）,also lower water holding capacity was scrutinized in 2 h,3 h and 5 h treatments （P〈0.01）. 【Conclusion】The results indicated that preslaughter exposure of broiler chickens to heat stress could induce breast muscle lower pH and oxidative damage,increase intramuscular fat and protein oxidation,also decrease solubility of muscle protein and water holding capacity,thus result in a greatly negative influence on myofibrillar protein gels.
出处
《中国农业科学》
CAS
CSCD
北大核心
2008年第6期1778-1785,共8页
Scientia Agricultura Sinica
基金
国家重点基础研究发展计划(“973”计划)(2004CB117505)
关键词
氧化
蛋白质
功能特性
热应激
鸡胸肉
Oxidation
Protein
Functionality
Heat stress
Broiler breast muscle
